Toy submarine



July 12, 1955 H. HIRSCH ETAL 2,712,710

TOY SUBMARINE Filed Feb. 17, 1955 INVENTORS HENRY H/RSCH By BENJAMl/V L. H/RSCH l E J :TTORNi Y5 United States Patent 9 TOY SUBMARINE Henry Hirsch and Benjamin L. Hirsch, Toledo, Ohio, assignors to Kellogg Company, Battle Creek, Mich., a corporation of Delaware Application February 17, 1955, Serial No. 488,856 -1 Claim. (CI. 46-94) The invention relates to a toy submarine that automatically and repeatedly submerges and surfaces when placed in water.

The present submarine contains a cavity which can be filled with a material that etfervesces in water. The submarine is slightly heavier than water so that when first placed in a vessel of water it sinks to the bottom. The gas generated as water reaches the effervescent material increases the buoyancy of the submarine to cause it to rise to the surface.

In the designing of such a submarine, it is difficult to achieve a construction such that upon the generation of a small amount of gas from the eifervescent material the submarine will rise to the surface, While remaining in an upright position so as to maintain a realistic appearance, and than upon reaching the surface will release a bubble of gas sufiiciently large so that the submarine again sinks to the bottom.

The principal object of the invention is to provide a toy submarine that is constructed in an economical manner to achieve the results mentioned above. cific objects and advantages are apparent from the following description, in which reference is had to the accompanying drawing showing a preferred embodiment of the invention.

Figure I of the drawing is a perspective view of a toy submarine.

Figure II is a bottom view thereof.

Figure III is a vertical section on the line III-III of Figure II.

Figure IV is a vertical section on the line IV-IV of Figure II.

This specific drawing and the specific description that follows merely disclose and illustrate and are not intended to limit the invention.

The present submarine comprises a submarine body 10 of a material (preferably a plastic) whose density approximates that of water. It is possible to use for the submarine body a plastic such as polystyrene which has a density slightly greater than that of Water, but it is preferable to use a material such as polyethylene which has a density slightly less than that of water. For the purpose of the present description it will be assumed that the submarine body is molded from polyethylene.

In order to conserve material and also to facilitate control of the buoyancy of the submarine, the submarine body preferably is generally hollow and open at the bottom. Perforations 11 are distributed evenly over the deck of the submarine to prevent bubbles of air or gas from collecting beneath the deck. If a bubble were retained beneath the deck it would cause the submarine to tilt into an unnatural position in the water, and might destroy the ability of the submarine to submerge. In order to permit the escape of bubbles through the deck of the submarine, each of the holes should be not less than 5 inch in diameter. When the total area of the deck is 0.75 square inch, the total area of the holes should be not less than about .05 square inch.

More spe- The submarine body contains a sealed air chamber 12, and an open-bottom chamber 13 for holding a powder that eifervesces in water. When the submarine is upright, the open-bottom chamber is directly below the air chamber and preferably both chambers are centered on a vertical line through the center of gravity of the submarine body. In the preferred construction shown in the drawing, the submarine body comprises a single open-bottom chamber, having an upper portion of reduced width located in a conning tower 14, and a partition for sealing off such upper portion to form the air chamber 12. Preferably the partition is in the form of an aluminum disk 15 that is press-fitted against the shoulder that is present because of the reduced width of the upper chamber 12.

Fitting in the 'open bottom of the lower chamber 13 is an upwardly-dished flanged cap 16 (not shown in Figure 11) having a perforation 17 to admit water to effervescent material contained in the lower chamber 13.

The cap 16 is made of a material having a density greater than that of the submarine body. Although the cap may be made of a ceramic material such as glass, it preferably is made of brass or another metal having a density at least as great as that of aluminum. One

, important function of the cap 16 is that it acts in conjunction with the buoyancy of the sealed air chamber 12 to keep the submarine upright in the water. That function results from the fact that the sealed air chamber 12 tends to remain uppermost in the water While the cap 16, being of a material having a density greater than that of the submarine body, tends to remain lowermost.

The average density of the submarine, including the sealed air chamber 12 and the cap 16, should be greater than that of water so that the submarine normally sinks, and surfaces only under the influence of gas generated by effervescent material in the lower chamber 13.

It has been found that when the lower chamber 13 of a submarine constructed as herein described is filled with an effervescent material and the submarine is placed in a vessel of water, the submarine will sink to the bottom while remaining in an upright position. The collection in the cap 16 of gas generated by the effervescent ma terial then will cause the submarine to rise to the surface while still maintaining its upright position. After the submarine reaches the surface, the bubble of gas in the cap 16 will continue to grow until it finally becomes so large that it is released. Moreover, when such release of the bubble occurs, the size of the bubble released is always large enough so as to permit the submarine again to sink to the bottom of the vessel.

In order to operate in the manner described, a submarine constructed as shown in the drawing that is slightly more than two inches long and contains 1.39 grams of polyethylene should have a sealed air chamber having a volume not greater than about 0.14 cc. nor less than about 0.1 cc. The capacity of the lower chamher is preferably about 0.0115 cubic inch.

It has been found that when the submarine is held in aninverted position and an effervescent powder is poured into the lower chamber 13, the powder is in a loose state so that it is not readily wet by water entering through the perforation 17. Therefore, the cap 16 preferably is constructed with a shoulder 18 that permits the cap to be inserted into the chamber 13 to a depth of about 5 inch. Such insertion of the cap 16 compresses the efiervescent powder to about of its original volume so as to render the powder more susceptible to uniform wetting, thus resulting in a steadier generation of gas.

It has been found that in order to permit water to enter the lower chamber and yet to prevent loss of the powder from the lower chamber, the perforation in the cap should have a diameter of about .06 to .085 inch. In order to insure satisfactory operation of the submarine, it is necessary to immerse the cap in water before it is inserted to retain the efiervescent powder. When the cap is thus immersed in to pick up enough Water to produce the necessary priming effect. As a result, the powder near the perfoe ration 17 is moist and water will continue to enter the lower chamber 13 until solved.

It has been found also that the size of the gas. bubble released is sufllcient to cause the submarine to sink if the over-all diameter of the cap 16 is 0.4 inch and the width of the flange around the cap is about .06 inch, the internal diameter of the cap being about 0.26 inch.

The effervescent material used maybe Seidlitz powder or an efiervescent citrate compound, but baking powder is preferred. Any baking powder may be used, one baking powder formula being 47% by weight of mono ammonium phosphate, 43% of sodium bicarbonate and 10% of corn starch.

water, it has been found 7 all of the powder has been dis- Col Having described the inventiomwe claim: r

A toy submarine comprising, in combination, a submarine body of a material whose density is slightly less than that of water, having a sealed air chamber, and an open-bottom chamber for holding a powder that efiervesces in water, the open-bottom chamber being directly below the air chamber when the submarine is upright, and an upwardly-dished, perforate, flanged cap for the lower chamber, of a material having a density greater than that'of the submarinevbody, the average density of the submarine, including the air chamber and the cap, being greater than that of water; and the upwardlydished portion of the cap being shaped totelescope into the open bottom of the lower chamber far enough so that when the lower chamber has been filled with powder the insertion of the cap compresses the powder to about three-fourths of its original volume.

0 References Cited in the file of patent FOREIGN PATENTS 1 240,230 Germany Oct. '31, 1911 

